Sectional induction heating coil



24, 1956 T. w. KALBOW 2,756,315

SECTIONAL INDUCTION HEATING COIL Filed July 29, 1953 2 Sheets-Sheet 1 1a 16 567/, if 20 July 24, 1956 T. w. KALBOW SECTIONAL INDUCTION HEATING COIL.

2 Sheets-Sheet 2 Filed July 29, 1955 a 4% g I w J, 0 0 6 6 J? 0 v 4 n& M w w a 0 flwn J 6 w J 7 Q d 9 $7 I M 4 E J a z 7 1 MW 2 V w m @mm w M 0" ,6 T u r1 H y fl x A MM -HI M 1 I. M W W M w United States Patent O SECTIONAL INDUCTION HEATING con.

Theodore W. Kalbow, Chicago, Ill., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application July 29, 1953, Serial No. 370,970

7 Claims. (Cl. 219-'10.79)

This invention relates to induction heating coils and more particularly to a high frequency heating coil having a section thereof removable to permit the movement of a part into and out of the coil.

It is an object of the present invention to provide an improved sectional induction heating coil having a removable section therein to permit the quick insertion and removal of parts into and out of the coil.

It is a further object of the present invention to pro- Vide a sectional induction heating coil having a pair of relatively fixed sections and a removable section provided with surfaces of relatively large area in abutting engagement with one another and having means for securing the removable section in tight engagement with the other sections.

In accordance with one embodiment of the invention there is provided a pair of relatively fixed coil sections disposed in spaced relation to each other and a removable coil section removably secured to and having a relatively large surface thereof in contact with said fixed coil sections. Each of the fixed coil sections is provided with a dove-tailed slot, including a pair of sloping wedge surfaces and an interconnecting surface, and the removable section has end portions shaped to provide surfaces conforming to and engageable with one of said sloping wedge surfaces and the intermediate surface of each of the fixed sections, and the removable section has a pair of wedge blocks guided for movement thereon toward and away from each other with a sloping surface of the wedge blocks engageable with the other sloping wedge surfaces of the fixed sections, and a threaded member operatively connected to the wedge blocks is rotatable to actuate the wedge blocks to secure the removable sections in tight engagement with the fixed sections and to release the removable section therefrom.

Other objects and advantages of the present invention will become apparent by reference to the following detailed description and the accompanying drawings, illustrating a preferred embodiment thereof, in which Fig. l is a front elevational view of a portion of a brazing device showing an article in position to be brazed and showing the heating coil in section;

Fig. 2 is a side elevational view of the brazing apparatus shown in Fig. 1;

Fig. 3 is an enlarged plan view of the sectional induction heating coil;

Fig. 4 is a plan view of the fixed sections of the coil with the movable section removed therefrom and with portions of one coil shown in section;

Fig. 5 is a plan view of the removable coil with parts thereof shown in section;

Fig. 6 is a vertical transverse sectional view taken on the line 6-6 of Fig. 3; and

Fig. 7 is a vertical sectional view taken on the line 7--7 of Fig. 3.

' The present sectional induction heating coil 10 is used for heating articles, such as a magnetron 12, which can not be moved into the coil in an axial direction, but

ice

which require the movement of the article into the coil in a direction transversely of the axis thereof. As shown in Fig. 1, the magnetron has a component 13 which rests on a component 14 with a ring 15 of brazing material therebetween which is to be heated to braze the components 13 and 14 together. The component 13 of the magnetron is held in a predetermined angularly aligned position on the component 14 by an L-shaped aligning bracket 17, the vertical leg 18 of which is removably secured to a base flange 20 of the magnetron. The magnetron 12 is adapted to be supported on a fixture 21 which is mounted on a table 22 and is adapted to support the components 13 and 14 in the opening of the coil 10 and to cool the component 14 during the brazing operation.

The sectional coil 10 comprises a pair of relatively fixed sections 25 and 26, and a removable section 27 (Figs. 3, 4, and 6). The fixed coil sections 25 and 26 are supported by a pair of tubular conductors 29 which are bonded to the rear end portions of the fixed coil sections and extend through the table 22 and have laterally projecting portions 30 which are secured to a pair of terminals'31 of a high frequency current generating device (not shown). In placing a magnetron in operative position in the coil 1!), the removable coil section 27 is detached from the coil 10 and the magnetron is moved horizontally into the opening in the coil and seated on the supporting fixture 21, which supports it in a predetermined position within the coil with the relatively fixed coil section 26 disposed between the vertical leg 18 of the aligning bracket 17 and the components 13 and 14 of the magnetron. The removable section 27 is then placed between the ends of the fixed sections 25 and 26 and secured thereto to form a single coil surrounding the juncture of the components 13 and 14.

The fixed sections 25 and 26 of the coil each comprise elongated straight portions 32, laterally curved portions 33, and forwardly directed arms 34. The arms 34 are provided with dove-tailed slots 35 having sloping end surfaces 36, 37 and an intermediate straight surface 38. The sloping surfaces 36 and 37 are in diverging relation to each other and the intermediate surfaces 38 are also disposed in diverging relation to each other. The removable section 27 is adapted to fit between the arms 34 of the fixed coil sections and has end surfaces 39 and sloping surfaces 40 conforming to and adapted to engage the surfaces 36 and 38, respectively, of the dovetailed slots 35. When the coil sections 25, 26, and 27 are in assembled relation, curved surfaces 41 on the sections cooperate with each other to form an opening conforming to the cross-section of the part which is to be inserted therein. 1

Means are provided for holding the coil sections in assembled relation and for pressing the sections into tight engagement with one another to establish and insure a good electrical connection between the several sections. As shown herein, the removable section 27 has a pair of U-shaped guide members 44 secured thereto, as indicated in Figs. 5 and 6, to form guideways for supporting a pair of wedge blocks 46 for movement toward and away from each other in a direction transversely of the arms 34. The wedge blocks 46 have sloping surfaces 47, which are engageable with the sloping surfaces 37 on the arms 34 and the wedge blocks 46 have threaded holes 48 for receiving the threaded ends 49 of an actuating member 50. The actuating member has an enlarged knurled head 51, by means of which the actuating member 50 may be rotated to impart movement to the wedge blocks 46. A tool (not shown) may be inserted in holes 52 in the knurled head 51 to aid in rotating the actuating member 50. It will be understood that the opposite ends of the threaded members 49 and the associated threaded holes 48 in the wedge blocks are threaded in opposite directions so that, in

response to the rotation of the member 50, the wedge blocks are caused to move either toward each other or away from each other.

Means are provided for supporting the removable section 2'7 on the fixed sections 25 and 26 in horizontal alignment therewith. Edge portions 54 of the upper plate of the U-shaped guide members 44 project beyond the ends of the removable section 27 and rest on theupper surface of the arms 34 of the fixed sections 25 and 26. The end portions 55 of the wedge blocks 46 are reduced in thickness and the lower faces thereof are adapted to engage and be supported on the upper faces of shelves 56 on the arms 34 extending outwardly from the surfaces 37 and 38 of the dove-tailed slots therein (Figs. 4 and 6).

Each of the fixed coil sections has a passageway 57 formed therein which is in communication at one end thereof with the interior of the tubular conductor 29 and extends forwardly a substantial distance along the arm and joins another passageway 58 which extends rearwardly a substantial distance and is connected to a short pipe 59. A hose 62) connected to the ends of the pipes 59 on the coil sections 25 and 26 conducts coolant from one coil section to the other. Conduits 62 connected to the lower end of the tubular conductors 29 are connectible to means for supplying coolant thereto, whereby coolant is circulated through the fixed coil sections 25 and 26 and the tubular conductors 29 to cool the coil during the brazing operation.

When it is desired to braze the component 13 to the component 14 of the magnetron, which components, as previously-stated, are held in aligned position relative to each other by the positioning bracket 17, the movable coil section 27 is removed from the stationary sections 25 and 26 of the coil 10 and the magnetron 12 is moved laterally relative to the coil, with the components 13 and 14 moving between the arms 34 of the fixed coil sections and 26, and the arm 34 of the coil section 26 entering the space between the components 13, 14, and the arm 18 of the positioning bracket 17. The magnetron 12 is then seated in the fixture 21 and supported thereby in a predetermined position with the components '13 and 14 in coaxial alignment with the opening in the coil 10. The removable section 27 is then replaced between the arms 34 of the fixed coil section and in assembled relation thereto as shown in Figs. 3 and 6, after which the actuating member 56 is rotated to cause the movement of the wedge blocks 46 towards each other. As the wedge blocks 46 are moved towards each other the sloping surfaces 47 thereon react against the sloping surfaces 37 on the fixed coil sections 25 and 26 to urge the removable section 27 in one direction and the fixed sections 25 and 26 in the opposite direction to establish a firm contact between the sloping surfaces 40 and 36, 39 and 38, and 47 and 37 of the removable and fixed coil sections. The movement of the wedge blocks 46 toward each other also serves to pull the arm portions 34 of the fixed coil sections 25 and 26 toward each other and against the end surfaces 39 of the removable section 27 and into tight engagement therewith. Thus, the abutting surfaces 36, 39, and 47 on each end of the removable coil section 27 and the cooperating abutting surfaces 36, 38, and 37 of the fixed coil sections are drawn into tight engagement with each other, and inasmuch as the areas of these abutting surfaces are relatively large, an effective low resistance electrical contact is established between the removable and the fixed coil sections.

it is to be understood that the above-described arrangements are simply illustrative of the application of the of end sections connectible to a source of high frequency current and disposed in spaced relation to each other, a removable intermediate section fitting between portions of said end sections, said end sections and said removable section having surfaces of relatively large area engageable with one another, a pair of elements mounted for movement on said removable section and engageable with said end sections, and means on said removable section for simultaneously moving said elements toward each other to effect the stressing of the end sections toward each other into tight engagement with said removable section.

2. A sectional induction heating coil comprising a pair of end sections connectible to a source of high frequency current and having portions thereof in close proximity to each other and provided with recesses forming a portion of an opening of predetermined outline in the coil for receiving an article to be heated therein, said pair of end sections having arms extending therefrom in spaced and substantially parallel relation to each other to provide clearance for the movement of said article therebetween to a predetermined position within the opening in said coil, a removable section having a pair of end surfaces adapted to be positioned between and in abutting engagement with the arms on said end sections and having a recess cooperating with the recesses in the end sections to form said opening in the coil, a pair of movable elements mounted on said removable section and engageable with portions of the arms of said end sections, and means on said removable section for moving said elements to stress said arms towards each other into tight engagement with the end surfaces of said removable section.

3. A sectional induction heating coil comprising a pair of end sections disposed in spaced relation to each other and a removable section, said end sections and said re movable sections having portions thereof engageable with each other to form a single coil with an opening for receiving therein an article to be heated, each of said end sections having a dove-tail slot therein disposed in opposed relation to each other, a pair of wedge blocks movably mounted on opposite ends of said removable section, said removable section and the Wedge blocks thereon being shaped to provide dove-tail portions adapted to fit in the dove-tail slots in the end sections with the wedge blocks engaging one sloping end surface of each of the dove-tail slots, and means carried by said removable section for simultaneously imparting movement to said wedge blocks to cause the end sections to be clamped into tight engagement with said removable section.

4. A sectional induction heating coil comprising a pair of relatively fixed sections disposed in spaced relation to each other and a removable section, said fixed sections and said removable sections having portions thereof engageable with each other to form a single coil provided with an opening for receiving therein an article to be heated, each of said fixed sections having an arm thereon, said arms being spaced from each other a distance greater than said opening, each of said arms having a dove-tailed slot therein forming a pair of sloping end surfaces and an intermediate connecting surface therebetween, said dove-tailed slots being disposed in opposed relation to each other, said removable section having a portion on each end thereof conforming to a portion of said dovetailed slot and including a sloping surface engageable with one of said sloping surfaces on the arms and an end surface engageable with a portion of the intermediate surface of a fixed section, a pair of wedge blocks, each of said wedge blocks having a threaded recess therein and a sloping surface engageable with the second sloping surface of the removable section, said removable section having guide means thereon for guiding said blocks for sliding movement toward and away from each other, and a rotatable actuating member having threaded portions cooperable with the threaded recesses in the blocks for moving said wedge blocks and causing the removable section to be secured to the fixed sections of the coil with their abutting surfaces in tight engagement.

5. A sectional induction heating coil comprising a pair of relatively fixed coil sections connectible to a source of high frequency current and having portions thereof in close proximity to each other and provided with recesses forming a portion of an opening of predetermined outline in the coil for receiving an article to be heated therein, said pair of relatively fixed coil sections having arms extending therefrom in spaced and substantially parallel relation to each other to provide clearance for the move ment of said article therebetween to a predetermined position with a portion of the article in the recesses in said relatively fixed sections, said pair of relatively fixed sections having a pair of first opposing clamping surfaces and a second pair of surfaces disposed transversely of said first surfaces to form a pair of shoulders adjacent said opening, a removable coil section having a pair of opposed first surfaces and a pair of second surfaces disposed transversely tosaid first surfaces engageable with the first pair and the second pair of surfaces, respectively, of the fixed sections, said removable section having a recess cooperating with the recesses in the fixed sections to form said opening in the coil, cam elements formed on the ends of said arms, a pair of movable cam members mounted on said removable coil section engageable With said cam elements, and means on said removable section for actuating said cam members to force said removable section into tight engagement with said shoulders and to urge the arms of the fixed sections into tight engagement with the removable section.

6. A sectional induction heating coil comprising a pair of end sections disposed in spaced relation to each other and a removable intermediate section, said end sections and said intermediate sections having portions thereof engageable with each other to form a single coil, each of said fixed sections having a dove-tailed slot therein providing a pair of sloping end surfaces and a connecting surface therebetween, said intermediate section having a portion on each end thereof conforming to a portion of said dove-tailed slot and including a sloping surface engageable with one of said sloping surfaces of said end sections and an end surface engageable with a portion of said connecting section of said end section, a pair of wedge blocks, each of said wedge blocks having a sloping surface engageable with the second sloping surface of each of the end sections and operable to impart relative movement between the sections and cause the end sections to be urged towards each other into tight engagement with the end portions of the intermediate section in response to movement of said Wedge blocks towards each other, said intermediate section having guide means thereon for guiding said Wedge blocks for sliding movement toward and away from each other, and means for imparting movement to said wedge blocks.

7. A composite inductor for heating articles comprising a pair of inductor sections, an intermediate inductor section fitting between portions of said pair of inductor sections, said intermediate inductor section and said pair of inductor sections having conforming surfaces in abutting relation one to another and having cooperating recesses forming an opening for receiving an article to be heated, said intermediate inductor section being removable to permit the movement of the article into said opening, and means on said intermediate inductor section engageable with said pair of inductor sections for stressing them toward each other to clamp the intermediate inductor section therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 2,264,301 Denneen et a1 Dec. 2, 1941 2,481,008 Gagliardi et a1 Sept. 6, 1948 2,528,714 Wadhams Nov. 7, 1950 2,643,325 Body June 23, 1953 2,665,367 Seulen Jan. 5, 1954 

